code: def _chi2_cumulant(n, df):
      assert n > 0
      return 2 ** (n - 1) * factorial(n - 1) * df
  
imports: import warnings
  import numpy
  from numpy.testing import assert_equal, assert_raises, assert_allclose
  import numpy.testing
  from scipy.special import gamma, factorial, factorial2
  import scipy.stats
  from statsmodels.distributions.edgeworth import _faa_di_bruno_partitions, cumulant_from_moments, ExpandedNormal
label_desc: Use image node_id 4 for calling a global function with example usage: _chi2_cumulant(n, df) and returns: unknown